bfs-3.js

class Queue {
    constructor() {
        this.items = [];
    }

    enq(obj) {
        this.items.push(obj);
    }

    deq() {
        return this.items.shift();
    }

    isEmpty() {
        return this.items.length === 0;
    }
}

// var Queue = function() {
//     this.items = [];
// };
// Queue.prototype.enq = function(obj) {
//     this.items.push(obj);
// };
// Queue.prototype.deq = function() {
//     return this.items.shift();
// };
// Queue.prototype.isEmpty = function() {
//     return this.items.length === 0;
// };


class Node{
  constructor(value,neighbors=[]){
    this.value        = value;
    this.neighbors    = neighbors;
    this.distance     = null;
  }
}


var node5 = new Node(5);
var node4 = new Node(4);
var node3 = new Node(3);
var node2 = new Node(2);
var node1 = new Node(1);

node5.neighbors = [node3]; 
node4.neighbors = [node3];
node3.neighbors = [node1,node4,node5];
node2.neighbors = [node1];
node1.neighbors = [node2,node3];


/* 
An undirected graph. Print out each node and it's distance from the source
    1
  /	   \
  2      3
        /   \
       4     5

*/


var bfs = (node) => {
  var q = new Queue();
  q.enq(node);
  node.distance = 0;
  console.log("Node " + node.value + " is " + node.distance + " from " + "Node " + node.value + "(source)" );
  while(!q.isEmpty()){
    var currentNode = q.deq();
    
      
    currentNode.neighbors.forEach((neighbor) => { 
      if (neighbor.distance === null) {
        neighbor.distance = currentNode.distance + 1;
        console.log("Node " + neighbor.value + " is " + neighbor.distance + " from " + "Node " + node.value + "(source)" );
        q.enq(neighbor);
      }
      
    });      
  }
};

bfs(node1);